1. Field of the Invention
The present invention relates to a process for preparing di-amino-polyalkenyl eithers, including those which are severly sterically hindered by reacting (a) an acyclic primary or secondary amine or a heterocyuclic amino compound with (b) a polyalkenyl either glycol or a polyalkenyl amino either alcohol, in the presence of a hydrogenation catalyst at elevated temperatures and pressures. The resulting di-amino-polyalkenyl eithers are useful in acid gas scrubbing, particularly in the selective removal of H.sub.2 S from gaseous streams containing CO.sub.2 and H.sub.2 S.
2. Description of Related Patents and Publications
Recently, it was shown that di-severely sterically hindered amino-polyalkenyl-ethers are superior agents for scrubbing H.sub.2 S from gaseous streams containing the same, especially in selectively removing H.sub.2 S from normally gaseous mixtures containing CO.sub.2 and H.sub.2 S. Such processes are disclosed in U.S. Pat. Nos. 4,405,482 and 4,405,583, both incorporated herein by reference. The art teaches that these compounds may be prepared by reacting the appropriate primary amine with a bis-(haloalkoxy)alkane or bis-sulfonate ester of a glycolic ether under conditions such that the haloacid or sulfonic acid is eliminated. This process is more fully disclosed in allowed U.S. Ser. No. 339,899 filed Jan. 18, 1982, the disclosure of which is incorporated herein by reference. Disadvantages of such processes include relatively expensive raw materials and product isolation. That is, the initially formed product is an amine salt which requires caustic treatment as a part of the product isolation procedure.
Consequently, there exists a need in the art for methods of preparing di-severely sterically hindered amino-polyalkenyl ethers which would not be limited by such disadvantages.